Communicating system



W M BACON ETAL COMMUNICATING SYSTEM n Original Filed Dec. 30, 1938 July1o, 1951 [.F WATSON sy t ATTORNEY Patented July 10, 1951 COMMUNICATINGSYSTEM Walter M. Bacon, New York, and Edward F. Watson, Larchmont, N.Y., assignors to Bell Telephone Laboratories, Incorporated, New York, N.Y., a corporation of New York Original application December 30, 1938,Serial No.

248,426. Divided and this application September 25, 1948, Serial No.51,2 28

2 Claims.

This invention relates to communication systems and more particularly toswitching and interconnecting arrangement for telegraph systems. Thisapplication is a division of our copending application Serial No.248,426, led December 30, 1938, now Patent 2,495,682, patented Jan. 31,1950. An object of the invention is to reduce the switching timerequired to switch successive mes- Asages to successive lines of astorage controlled automatic telegraph switching system. Y Anotherobject is to provide a switching arrangement in which switching controlmeans, operating in response to a conditioning code combination, whichmay be otherwise called a preparatory code combination, preparesswitching circuits for subsequent correct response to a dis- V 'connectcode combination, which may otherwise invention fulfilling the foregoingand other objects and including the foregoing features of thisvinvention may be more readily understood from :the followingdescription, when read with reference to the attached drawing in whichthe single iigure of the drawing discloses the novel features ofapparatus exemplifying the invention with cooperating elements ofwell-known construction and operation disclosed partially in detail andpartially diagrammatically.

The arrangement disclosed in the drawing consists of an incomingconductor pair 203B. over which signals are received from a transmitter|300 diagrammatically illustrated. For the purpose of the presentinvention this transmitter may be any one of a number of conventionaltypes of telegraphic start-stop iive unit permutation code transmitterssuch as are disclosed or referred to in the parent specification aboveidentined. For the purpose of the present invention it may be assumedthat this transmitter is connected to the receiving line 203B. at anysuitable point for the purpose of emitting such start-stop ve unit codesignals thereupon and it may preferably be a tape controlledtransmitter. The manner in which such a tape controlled transmitterbecomes connected to such a receiving line to emit signals thereupon isfully disclosed in the parent application but the present invention doesnot depend upon the manner in which this is done; indeed, it may beassumed that the transmitter is permanently connected to the line. The

incoming line 203R is connected through the operating winding of thereceiving relay |30| in series with certain normally closed contacts ofrelays |336, |331 and |338. The apparatus disclosed in the rectangledotted in the upper right three-quarters of the iigure is assumed to belocated at a station K. Other stations L and M are duplicates of thoseelements of staton- K which are in the upper left quarter of thedrawing. Stations L and M are assumed to be in oilices remote from thestation K and are connected thereto by receiving branch conductors LRZand LRS. The receiving apparatus at station K is likewise connected by areceiving branch conductor LRI. However, any of the lines LRI, LR2 andLR3 may be long or short and may terminate in the same or a differentoilice without departure from the mode of operation of the apparatus orfrom the principle of operation ol the invention; furthermore, othersimilar stations may be provided in an obvious manner.

The drawing includes a disclosure of transmitting lines LRd, LRS and LRSby which the transmitting apparatus of any of stations K, L or M may beconnected to an outgoing conductor pair 203S for transmission in anoutgoing direction over said conductor pair. The manner of 'Operation ofthis transmitting equipment is fully disclosed and the essential andnovel features thereof claimed in the aforesaid parent application.Inasmuch as the inventive features claimed hereinafter do not dependupon the presence of this transmitting equipment or its mode ofoperation they will not be further described herein. A full descriptionis found in the parent speciiication referred to above.

At the station comprising the right-hand portion of station K connectedto the receiving branch of the party line 203B., the armatures of thereceiving relay |30| is operated to its spacing positions in response tothese spacing impulses transmitted by the automatic transmitterdescribed above. The operation of this relay to its spacing positioninterrupts an obvious circuit through the respective selector magnet|349. This selector magnet is somewhat similar to the printer magnets ofa teletypewriter mechanism and controls a selector mechanism which isessentially the same as the selector mechanism of a printing telegraphreceiving instrument. However, for the purpose of controlling switchingoperations, instead of causing characters to 4be printed, this selectormechanism is arranged to selectively control and close certain contactsin 3 response to reception of permutation code combinations andtelegraph impulses.

This permutation code selector is provided with a number of contactswhich are selectively controlled by the permutation code selector. It isprovided with a contact which is controlled by a movable member whichcorresponds to a platen of a teletypewriter. When this platen member isoperated to its figures or upper case position, it closes a contactcontrolled thereby-and maintains this contact closed as longas thismember remains in its figure position. When this .member is returned bythe selecting mechanism to its letters position or lower case, it willopen this contact. This selector at lall of the subscribers stations isalso provided -with a contacthereinafter referred to as a universalcontact which momentarily operates once for each code combinationreceived by the selecting mechanism. In the preferred embodiment of thisinvention `.fthis.contact is 4preferably operated by thelockingcimemben-lwhichilocks each received selection on i@ the-ipermutationelements which are sometimes .g., ,:alled.;,codebars.A However, vthiscontact may be A, fcontrolledaby Vany member of the selectingapggparatusgwhich,bperates onceand at anzapprol-flllriate; time for eachcode combination received. ifi Eorgexamplm; this Acontact may becontrolled -tf-.rom acam mounted on the selectionV cam shaft moritfmay.;becontrolled by a cam mounted on the .uf-unctionrshaftror by theprinting bail or any otherssuitablepv element which operates once foreach received code combination.

A ?Ehegremaining contacts controlled by the perggmutation code selectorlcontrolled by magnet |349 his preferablycontrolledby the code barsselected ggby; theg-received-code combinations.. These codefmbarsjinstead-of operating type bars as in a tele- -,tygpewriterorreceiving telegraph printing appa- Rratus cause ,thecontacts associatedwith them to -ifbemomentarily operated. The selecting equipggnentghascontactsassociated with a particular greleasqcodefban for example', thecode bar which rqwould -normally; operate the letter V-type bar of,vfthateletypewriter. The-,selecting equipment has r,.(an.. .lactivating contact whichis similarly congtrolledgbythe same pull bar at each ofthe statipnsa,s, forexample, the pull bar which normally operates theletter X-type bar.

Vgllt-gobtlieother contacts .for switching seleci tivelythe. source ofsignals comprising the line 'pa'th 2 03R,`.to.oneorganother of thereceivers of Hifi-MBS K, L or M may bek operated by diierent I,.,pullbars. ,For.example,. to connect on station K,

,Qntactsmaygbeassociatedtwith -the K pull to-v connect on station Lcontactsjmaybe operated .,by, theL p ull bar to connect on station Mcontacts u,' niayqbe operatedjby the M pullbar,vetc.for any other-1,stations,- if fany, which may be controlled .bx ,the.Selectorg'f'jlhedetailsofi-the selecting mechanism have not beenshownbecause they are'well known and 73operatgin-their ,usual manner.For a detailed ,description vof devices of this kind, reference may,gbeghadtothe following United States-patents, the,iisclosuresbf,whichare hereby made a part of ,gthisHpresent:specification as if -ully included ,herein. 2,112,234 granted toBeattie et al., March 29, 1938,;and 2,120,235 granted to Beattie et al.,,June l4,.1938. .Of course, the circuits controlled ,by.the selector,.contacts in the present applicardtion operate differently than thecircuits conmtrolled,by. the selector contacts in these patents.tAs,,s|ated, in Beattie et al. Patent 2,120,235, the

4 various pull bars of the selecting mechanisms oi* teletypewriters maybe used for performing their regular printing functions in response tolower case selections.

5 The details of operation the circuit arrangements in accordance lwiththis invention which are controlled by the selector contacts will be cdescribed in detail with reference to the circuits shown in the solegure of the drawing and located at station K. For the purpose ofillustrating operationsin accordance with the present invention, it maybe assumed that the transmitter |300 is emitting onto the line 203B a,sequence of permutation ccde combinations in which each mesl5 sage endswith a letters character followed by a figures code combination, anactivate code combination, which we may assume is that corresponding tothe letter X, a disconnect code, a switching code combination such as K,L

or NL followed by a message beginning with a n.fletteis code combination`which is again fol- .:lowed by a sequence consisting of figuresfactipvate, disconnect, a switching code combination i and anothermessage.

"The figures combination when it is repeated and. transmitted over thereceiving channel of the parw line 203B. will be received by theselecting mechanism at station K. Receiving relay Avof. the permutationcode selector'follows the im- 30 pulses received over the receivingchannel of the party. line 2031?, and repeats them to the selectingmagnet |302. Selector magnet |302 actuatesthe selecting mechanism andcauses it to close the --contacts |329. Contacts |320 are controlledvbya member which corresponds in its motions to -lrthe motionsof the platenof a. teletypewriter.

The platen of the teletypewriter when shifted to the gure positionremains in this position until unshifted by a later code combination.The con- `-0itacts1|32ll are arranged to remain closed so long r as theplaten-like member remains in the shifted or gures position.

The next code combination transmitted from thesubscribers station andrepeated through .45fthecentral station will be an activatingcodeucombination which will momentarily close con tacts |32I. 'The operationof contacts |32| com- ..pletes a circuit for the operation of relay'|326 D lfrom ground through the operated contacts |320 .50 Aand |32| tobattery through the winding of relay #1326. Operation of relay |326completes a circuit for1 maintaining itself operated from ground throughcontacts |320 and operated left-hand contacts of relay A|326 to batterythrough the .55; windings of relay`1|326. The next code combi- 2 nationtransmitted from the subscribers station `and-.received by the selectorat station K'will -be a code combination selecting the particular sta-.tionfor which the message is intended. Since no: the message isintended for station K it will be fassumed that the next codecombination willbe -ithe same combination as assigned-to the letrteri'K5'When this code combination is received -iby the line relay |30| andrepeated tothe `selecting magnet |302, selecting magneti|302 will-cause'the selecting mechanism at station'K to momentarily closecontacts |324. The closing of contacts of |324 at this time completes acir- --cuit for the operation of relay |321 from ground 705.throughV theoperated contacts |320 and operat- =;ed right-hand and left-handcontactsofrelay `H326, the operated contacts |324 to` battery `throughthe windingof relay |321. Relay |321 operation completes a lockingcircuit-'from -fground'through its left-hand operated contacts,

the break contacts of relay |328 to battery through the winding of relay|321. The operation of relay |321 completes an obviouscircuit forlighting lamp |333 to indicate to the attendant at station K that thereceiving channel of the party line is connected to station K. Operationof relay |321 also completes a circuit for the operation of relay |336from battery through the winding of relay |336, the right-hand breakcontacts of relay |339 to ground through the right-hand operatedcontacts of relay |321.

Y The operation of relay |336 connects the receiving relay |348 to thereceiving channel of the party line 203. The next combinationtransmitted by the subscribers station which will be I writer unless theteletypewriter had been previously left in upper case in which case theletters signal will restore it to the lower case. At station K theselecting magnet |302 will follow these signals and will cause theselector to open the contacts |320 which in turn causes relay |326 torelease.

Thereafter the code combinations perforated in the tape 50| at thesubscribers station will be transmitted to the receiving teletypewriterat station K through the tape transmitter at station A, the transmittingchannel of party line the reperforator |002 and retransmitter I |0| atthe central station, the receiving channel of the party line 203 to theteletypewriter at station K where they are recorded. The line relayrepeats all of these impulses to the selector magnet |302. However,these impulses produce no effect upon the selector equipment because ithas not been activated. The selecting mechanism will close the variouscontacts when the respective code combinations are received. However,since the switching controlling relays operated by these contacts arenot properly operated to perform a switching operation the actuation ofthese contacts at this time produces no effect upon the line switchingrelays |336, |331 and |338.

At the termination of the message the subscriber at station A willperforate the figures signal combination in the tape followed by anactivating combination. The activate signal may be any available codebut as set forth hereinbefore may be the X code. The figures combinationwhen received at station K by the selecting magnet |302 will causecontacts |320 to operate. Then the activating signal combination willcause the selecting mechanism to momentarily close the activatingcontacts |32|. This completes a circuit for the operation of relay |326as described above. The next combination perforated in the tape by thesubscriber will be a disconnect signal, for example, the letter V. Whenthis disconnect signal is received by the selecting magnet |302 tostation K it will cause the selecting mechanism to momentarily close thecontacts |325. This completes a circuit for the operation of relay |328from ground through the operated contacts |320, the operated contacts ofrelay |326, the operated contacts |325 to battery through the windingsof relays |328, |330 The relay |348 will follow these and |332. Theoperation of relay's |330 and |332 in this circuit at this time producesno useful function. Operation of relay |328 interrupts the lockingcircuit of relay |321 and allows this relay to release. Relay |328 inoperating completes a locking circuit from ground through the left-handoperated contacts of relay |321 through its own operated contacts and awinding to battery which circuit insures that relay |328 will remainoperated sufficiently long to cause relay |321 to fully release. Therelease of relay |321 interrupts the circuit of relay |336 and permitsthis relay to release. The release of relay |321 also interrupts thecircuit of lamp |333 thus causing this lamp to be extinguished. Therelease of relay |336 disconnects the receiving relay |348 of thereceiving teletypewriter at station K from the receiving channel ofparty line 203 and reestablishes a local circuit through the upperwinding of the receiving relay |348 to maintain it in its markingposition thus maintaining the teletypewrter at station K in itsI normalcondition.

If the next message is intended for station L or M, the next signal overthe line from the transmitter |300T will be the letter L or M followedby a letters signal then followed by the message to the correspondingstation L or M. This would cause the selector controlled by theselecting magnet |302 to operate either relay |329 or |33! as the casemay be. The operation of these relays in turn will cause the operationof relays |331 or |338, respectively, to connect the receiving apparatusat station L or M to the receiving channel of the party line 203.

The characteristic feature of operation therefore is that thetransmitter |308, which may be any transmitter connected to line 203B,in any manner, transmits a sequence of characters consisting of amessage to any station K, L or M followed by a code combination whichactivates or readies the switching equipment, a code combination whichthen clears the connection to any connected station K, L or M thenestablished by releasing whichever of relays |336, |331 or |338 happensto be operated; then followed by a switching signal which connects onone or another of stations K, L or M, following which the messageintended therefor is transmitted whereupon the sequence of events may berepeated.

The specific manner in which a transmitter such as the transmitter |300may become connected to line 203R to transmit a series of messagesthereover intended for one or another of stations K, L or M is fullydescribed in the parent specification above referred to.

What is claimed is:

l. A telegraph switching system comprising a signal .source forsupplying sequences of message signals comprising an indefinite numberof messages each of which is followed by and separated from thesucceeding message by an activating signal, a disconnecting signal and aline connecting signal characterized in that means for switching thesaid messages selectively to any one of a plurality of outgoing linescomprises means iirst responsive to the activate signal for preparingfor reception of the disconnect signal, by means responsive to thedisconnect signal for disconnecting any one of said lines, and meansresponsive to the switching signal for selectively completing aconnection of said source with a predetermined outgoing line.

2. In a system for the automatic switching of telegraph messages, thecombination of a source 7 oftelegraph signals including a iady' signal,:a1-'clearing signaland a switching signal transmitted'inzadvance.of-the message characters, a plurality of outgoing .lines'switchingmeans for connecting said source to any one of said outgoing lines,means responsive to the receipt of saidireadysignal for. prepa-ring saidswitching means for.: operationv by,x said clearing signal,mean'siresponsiveto the receipt of said Aclearing signal for clearingall connection between said sourcefand:saidloutgoing lines, and meansresponsiveA to receipt of said switching signal foi completinga'connection between said source and a predetermined outgoing line.

WALTER M. BCON.

EDWARD F. WATSON.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS

